php - How can I access an array/object? -


i have following array , when print_r(array_values($get_user));, get:

array (           [0] => 10499478683521864           [1] => 07/22/1983           [2] => email@saya.com           [3] => alan [4] => male           [5] => malmsteen           [6] => https://www.facebook.com  app_scoped_user_id/1049213468352864/           [7] => stdclass object (                    [id] => 102173722491792                    [name] => jakarta, indonesia           )           [8] => id_id           [9] => el-nino           [10] => alan el-nino malmsteen           [11] => 7           [12] => 2015-05-28t04:09:50+0000           [13] => 1         )  

i tried access array followed:

echo $get_user[0]; 

but displays me:

undefined 0

note:

i array facebook sdk 4, don't know original array strucutre.

how can access example value email@saya.com array?

to access array or object how use 2 different operators.

arrays

to access array elements have use either [] or don't see much, can use {}.

echo $array[0]; echo $array{0}; //both equivalent , interchangeable 

difference between declaring array , accessing array element

defining array , accessing array element 2 different things. don't mix them up.

to define array can use array() or php >=5.4 [] , assign/set array/-element. while when accessing array element [] or {} mentioned above value of array element opposed setting element.

//declaring array $arraya = array ( /*some stuff in here*/ ); $arrayb = [ /*some stuff in here*/ ]; //only php >=5.4  //accessing array element echo $array[0]; echo $array{0}; 

access array element

to access particular element in array can use expression inside [] or {} evaluates key want access:

$array[(any expression)] 

so aware of expression use key , how gets interpreted php:

echo $array[0];            //the key integer; accesses 0's element echo $array["0"];          //the key string; accesses 0's element echo $array["string"];     //the key string; accesses element key 'string' echo $array[constant];     //the key constant , gets replaced corresponding value echo $array[constant];     //the key constant , not string echo $array[$anyvariable]  //the key variable , gets replaced value in '$anyvariable' echo $array[functionxy()]; //the key return value of function 

access multidimensional array

if have multiple arrays in each other have multidimensional array. access array element in sub array have use multiple [].

echo $array["firstsubarray"]["secondsubarray"]["elementfromthesecondsubarray"]          // ├─────────────┘  ├──────────────┘  ├────────────────────────────┘          // │                │                 └── 3rd array dimension;          // │                └──────────────────── 2d  array dimension;          // └───────────────────────────────────── 1st array dimension; 

objects

to access object property have use ->.

echo $object->property; 

if have object in object have use multiple -> object property.

echo $objecta->objectb->property; 

note:

  1. also have careful if have property name invalid! see problems, can face invalid property name see question/answer. , this one if have numbers @ start of property name.

  2. you can access properties public visibility outside of class. otherwise (private or protected) need method or reflection, can use value of property.

arrays & objects

now if have arrays , objects mixed in each other have if access array element or object property , use corresponding operator it.

//object echo $object->anotherobject->propertyarray["elementonewithanobject"]->property;     //├────┘  ├───────────┘  ├───────────┘ ├──────────────────────┘   ├──────┘     //│       │              │             │                          └── property ;      //│       │              │             └───────────────────────────── array element (object) ; use -> access property 'property'     //│       │              └─────────────────────────────────────────── array (property) ; use [] access array element 'elementonewithanobject'     //│       └────────────────────────────────────────────────────────── property (object) ; use -> access property 'propertyarray'     //└────────────────────────────────────────────────────────────────── object ; use -> access property 'anotherobject'   //array echo $array["arrayelement"]["anotherelement"]->object->property["element"];     //├───┘ ├────────────┘  ├──────────────┘   ├────┘  ├──────┘ ├───────┘     //│     │               │                  │       │        └── array element ;      //│     │               │                  │       └─────────── property (array) ; use [] access array element 'element'     //│     │               │                  └─────────────────── property (object) ; use -> access property 'property'     //│     │               └────────────────────────────────────── array element (object) ; use -> access property 'object'     //│     └────────────────────────────────────────────────────── array element (array) ; use [] access array element 'anotherelement'     //└──────────────────────────────────────────────────────────── array ; use [] access array element 'arrayelement'  

i hope gives rough idea how can access arrays , objects, when nested in each other.

note:

  1. if called array or object depends on outermost part of variable. [new stdclass] array if has (nested) objects inside of , $object->property = array(); object if has (nested) arrays inside.

    and if not sure if have object or array, use gettype().

  1. don't confused if uses coding style you:

    //both methods/styles work , access same data echo $object->anotherobject->propertyarray["elementonewithanobject"]->property; echo $object->         anotherobject         ->propertyarray         ["elementonewithanobject"]->         property;  //both methods/styles work , access same data echo $array["arrayelement"]["anotherelement"]->object->property["element"]; echo $array["arrayelement"]      ["anotherelement"]->          object    ->property["element"]; 

arrays, objects , loops

if don't want access single element can loop on nested array / object , go through values of particular dimension.

for have access dimension on want loop , can loop on values of dimension.

as example take array, object:

array (     [data] => array (             [0] => stdclass object (                     [propertyxy] => 1                 )                 [1] => stdclass object (                     [propertyxy] => 2                 )                [2] => stdclass object (                     [propertyxy] => 3                                   )             ) ) 

if loop on first dimension values first dimension:

foreach($array $key => $value) 

means here in first dimension have 1 element key($key) data , value($value):

array (  //key: array     [0] => stdclass object (             [propertyxy] => 1         )     [1] => stdclass object (             [propertyxy] => 2         )     [2] => stdclass object (             [propertyxy] => 3         ) ) 

if loop on second dimension values second dimension:

foreach($array["data"] $key => $value) 

means here in second dimension have 3 element keys($key) 0, 1, 2 , values($value):

stdclass object (  //key: 0     [propertyxy] => 1 ) stdclass object (  //key: 1     [propertyxy] => 2 ) stdclass object (  //key: 2     [propertyxy] => 3 ) 

and can loop through dimension want no matter if array or object.

analyse var_dump() / print_r() / var_export() output

all of these 3 debug functions output same data, in format or meta data (e.g. type, size). here want show how have read output of these functions know/get way how access data array/object.

input array:

$array = [     "key" => (object) [         "property" => [1,2,3]     ] ]; 

var_dump() output:

array(1) {   ["key"]=>   object(stdclass)#1 (1) {     ["property"]=>     array(3) {       [0]=>       int(1)       [1]=>       int(2)       [2]=>       int(3)     }   } } 

print_r() output:

array (     [key] => stdclass object         (             [property] => array                 (                     [0] => 1                     [1] => 2                     [2] => 3                 )          )  ) 

var_export() output:

array (   'key' =>    stdclass::__set_state(array(      'property' =>      array (       0 => 1,       1 => 2,       2 => 3,     ),   )), ) 

so can see outputs pretty similar. , if want access value 2 can start value itself, want access , work way out "top left".

1. first see, value 2 in array key 1

array(3) {  //var_dump()   [0]=>   int(1)   [1]=>   int(2)   [2]=>   int(3) } 

array  //print_r() (   [0] => 1   [1] => 2   [2] => 3 ) 

array (  //var_export()   0 => 1,   1 => 2,   2 => 3, ), 

this means have use []/{} access value 2 [1], since value has key/index 1.

2. next see, array assigned property name property of object

object(stdclass)#1 (1) {  //var_dump()   ["property"]=>     /* array here */ } 

stdclass object  //print_r() (   [property] => /* array here */ ) 

stdclass::__set_state(array(  //var_export()   'property' =>      /* array here */ )), 

this means have use -> access property of object, e.g. ->property.

so until know, have use ->property[1].

3. , @ end see, outermost array

array(1) {  //var_dump()   ["key"]=>     /* object & array here */ } 

array  //print_r() (   [key] =>      /* object & array here */ ) 

array (  //var_export()   'key' =>     /* object & array here */ ) 

as know have access array element [], see here have use ["key"] access object. can put these parts , write:

echo $array["key"]->property[1]; 

and output be:

2 

don't let php troll you!

there few things, have know, don't spend hours on finding them.

  1. "hidden" characters

    sometimes have characters in keys, don't see on first in browser. , you're asking yourself, why can't access element. these characters can be: tabs (\t), new lines (\n), spaces or html tags (e.g. </p>, <b>), etc.

    as example if @ output of print_r() , see:

    array ( [key] => here )  

    then trying access element with:

    echo $arr["key"]; 

    but getting notice:

    notice: undefined index: key

    this indication there must hidden characters, since can't access element, if keys seems pretty correct.

    the trick here use var_dump() + source code! (alternative: highlight_string(print_r($variable, true));)

    and of sudden maybe see stuff this:

    array(1) {   ["</b> key"]=>   string(4) "here" } 

    now see, key has html tag in + new line character, didn't saw in first place, since print_r() , browser didn't showed that.

    so if try do:

    echo $arr["</b>\nkey"]; 

    you desired output:

    here 
  2. never trust output of print_r() or var_dump() if @ xml

    you might have xml file or string loaded object, e.g.

    <?xml version="1.0" encoding="utf-8" ?>  <rss>      <item>          <title attribute="xy" ab="xy">test</title>      </item>  </rss> 

    now if use var_dump() or print_r() see:

    simplexmlelement object (     [item] => simplexmlelement object     (         [title] => test     )  ) 

    so can see don't see attributes of title. said never trust output of var_dump() or print_r() when have xml object. use asxml() see full xml file/string.

    so use 1 of methods shown below:

    echo $xml->asxml();  //and source code  highlight_string($xml->asxml());  header ("content-type:text/xml"); echo $xml->asxml(); 

    and output:

    <?xml version="1.0" encoding="utf-8"?> <rss>      <item>          <title attribute="xy" ab="xy">test</title>      </item>  </rss> 

for more information see:

general (symbols, errors)

property name problems


Popular posts from this blog

php - How should I create my API for mobile applications (Needs Authentication) -

5 Reasons to Blog Anonymously (and 5 Reasons Not To)

Google AdWords and AdSense - A Dynamic Small Business Marketing Duo